Thus, in an indirect-firing sealing apparatus, the nails are inserted into the gun of the apparatus, forward of the feeder, via a flexible feed tube extending between the downstream gun and an upstream hopper, which hopper is intended for receiving a magazine pack of nails that is dropped into and slid along the tube after the bottom of the hopper has been unlocked.
The flexible feed tubes are made from a transparent material so that the filling status of the feed tube can be ascertained. In point of fact, after a certain period of use and therefore of friction from the nails, essentially via their circular head, against the inner wall of the tube, this wall becomes opaque.